Answer:
r = 50[m]
Step-by-step explanation:
Since the instrument has an operating or range radius, we must calculate this working distance or radius. We can determine the working area with the values that were given to us.
![A=(70W)/(0.0089(w)/(m^(2) ) ) \\\\A=7865.16[m^(2) ]](https://img.qammunity.org/2022/formulas/physics/high-school/ursukd5utwfaucb84k2fqz1k4y9p91528k.png)
Now using the area of the circle we can find the radius.
![A=\pi *r^(2) \\7865.16=\pi *r^(2) \\\\r=\sqrt{(7865.16)/(\pi ) } \\r=50[m]](https://img.qammunity.org/2022/formulas/physics/high-school/k6vnwwj9f8hspqfacp7sfb00ubbhhi9r31.png)